Method and apparatus for filling bags or the like



Sept. 30, 1969 K. BISCHOFF METHOD AND APPARATUS FOR FILLING BAGS OR THELIKE Filed May 15.1967

3 Sheets-Sheet l IIIlllllllllIlIlllllillllll INVE N TOR: KARL IBISCHOFF'By MM saw,

his ATTORNEY A FIGZ K. BISCHOFF Sept. 30, 1969 METHOD AND APPARATUS FORFILLING BAGS OR THE LIKE 3 Sheets-Sheet 2 Filed May 15. 1967 INVENTOR:

L B/SCHOFF his ATTORNEY K. BISCHOFF Sept. 30, 1969 METHOD AND APPARATUSFOR FILLING BAGS OR THE LIKE Filed May 15. '19s? 3 Sheets-Sheet 3 UnitedStates Patent H 59,416 Int. Cl. B6511 9/16, 1/22 US. Cl. 53-37 16 ClaimsABSTRACT OF THE DISCLOSURE The present invention relates to a method andapparatus for filling bags or other types of deformable receptacles withflowable materials, particularly with pulverulent or granularsubstances. More particularly, the invention relates to a method andapparatus for filling bags or like deformable receptacles with flowablematerial in such a way that the charge of material in the interior of abag is tightly enclosed by the material of the bag so that the lattercan more readily assume and retain a desired shape and can be morereadily stacked in boxes or other types of containers for shipment orstorage.

Background of the invention One presently known method of completely ornearly completely filling a deformable bag with flowable materialincludes the use of a winding or twisting device which engages and rollsthe top part of a filled bag. Such method is not entirely satisfactorybecause, if the operation of the winding device is automatic, it makes acertain number of turns so that the appearance of finished bags and thequantity of air which might remain entrapped therein depend on thequantity of flowable material in the bag. The uniformity could beimproved by tamping the charges in successive bags to the same level andby trimming the top parts of filled bags so that each successive bagwould comprise a top part of identical length. However, the time,machinery and energy required for such operation would contributeexcessively to the cost of the ultimate product. Furthermore, twistingdevices cannot be used in connection with highly deformable bags ofpolyethylene or the like and they cannot guarantee complete expulsion ofair and/ or the formation of bags which are readily stackable in boxesor on shelves.

Accordingly, it is an important object of the present invention toprovide a novel and improved method of forming, filling and sealing bagsor like deformable receptacles for flowable materials in such a way thateach receptacle can be converted into a body of desired configurationfor convenient stacking in storage or transport.

Another object of the invention is to provide a novel and improvedmethod of expelling air from the interior of filled bags prior to finalsealing of such bag.

A further object of the invention is to provide a method of the justoutlined characteristics according to which the expulsion of air can becarried out simultaneously with other treatment of bags.

An additional object of the invention is to provide a method which canbe resorted to in connection with filling of flowable charges intofluidtight or permeable bags or like receptacles.

A concomitant object of the invention is to provide an apparatus whichcan be utilized in the practice of the above outlined method.

Another object of the invention is to provide an apparatus which can beused in the production of different types of bags and which can beoperated automatically or semi-automatically.

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A further object of my invention is to provide the apparatus with simplemeans for effecting expulsion of surplus alr from filled bags or likereceptacles.

Summary of the invention One feature of the present invention resides inthe provision of a method of filling bags or analogous deformablereceptacles with flowable materials, preferably with granular orpulverulent substances. The method comprises the steps of introducinginto a receptacle whose bottom and top ends are respectively closed andopen a charge of flowable material so that the charge fills the interiorof the receptacle to a desired level and that the remainder of thereceptacle still contains at least some air, evacuating air from theinterior of the receptacle by moving the material of the top part intoabutment with the top surface of the charge, and sealing the receptacleimmediately above the level of the charge so that all sides of thecharge are completely surrounded by the material of the receptacle andthat the charge completely fills the receptacle in the region below theseal. As a rule, the material-introducing step is carried out at a firststation and the filled receptacle is then transported to a secondstation at which the air is evacuated prior to sealing. The receptacleis preferably subjected to one or more vibrating, agitating or othershaking actions to compact the charge in its interior prior to expulsionof air above the level of the thus compacted charge.

If the receptacle consists of foraminous material which retains thecharge but permits the passage of air, the material of the receptacle issimply folded over the charge from two or more sides to provide atoppanel which overlies the charge, and the seal is formed directly abovethe panel. If the material of the receptacle is not permeable to air,its upper part above the level of the charge must be provided with oneor more openings or outlets for evacuation of air. This can be achievedin a number of ways. For example, the open top end of the filledreceptacle can be partially closed to provide one or more paths forevacuation of air through the resulting closure, and the material of thereceptacle is thereupon folded over the charge to expel air prior toscaling. It is also possible to completely close the top end of thefilled receptacle and to pierce the thus closed receptacle above thecharge to provide one or more punctures in the form of circular,slit-shaped or otherwise configurated openings for escape of air. Thepuncturing of the receptacle above the level of the charge can becarried out simultaneously with closing of the top end.

The receptacle preferably consists of heat-sealable synthetic plasticmaterial which can be sealed and closed by the application of heat andpressure. The means for respectively sealing and closing the receptaclepreferably comprise pairs of cooperating welding electrodes.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved apparatus itself, however, both as to its construction and itsmode of operation, together with additional features and advantagesthereof, will be best understood upon perusal of the following detaileddescription of certain specific embodiments with reference to theaccompanying drawing.

Brief description of the drawing FIGS. 1a to 1d illustrate four stagesin the formation of a tightly packed and sealed receptacle in accordancewith one embodiment of my method;

FIG. 2 is a side elevational view of a receptacle as it appears whenlooking in the direction of arrow X shown in FIG. 1a;

FIG. 3 is a side elevational view of a portion of an apparatus which maybe utilized in carrying out the method of my invention; and

FIG. 4 including FIGS. 4a-4d illustrate four stages in the operation ofthe apparatus shown in FIG. 3.

Description of the preferred embodiments FIGS. 1a to 1d illustratecertain details of an apparatus which can be utilized in the practice ofmy method. This apparatus comprises a suitable bag forming and fillingmachine which maybe similar to that disclosed, for example, in US.Patent No. 2,113,636 to Vogt or in U.S. Patent No. 2,960,808 to Pike.The filling machine comprises a pair of cooperating closing electrodes 2disposed at a level below a mandrel 2m which feeds charges of liquid,granular or pulverulen't material into successive lengths of acontinuous tube 2t. The tube is severed at a level above the bag 1'.During evacuation of air via slit 4, the bag 1 whose bottom ends aresealed at 1a and whose top ends are closed or sealed at 1b. The fillingmachine may comprise two pairs of closing electrodes 2 and 2a and areciprocable knife 2b which moves into the gap between the electrodes 2,2a to sever the bag 1 from the lower end 1a of the remainder of the tube2:. The electrodes 2a form the closed lower ends 1a, 1a and theelectrodes 2 form the closed top ends 1b. These electrodes are disposedat a first station I which is a filling and closing station and at whichthe bags 1 are formed one after the other.

In accordance with the feature of my invention, the station I furtheraccommodates a reciprocable, turnable or rockable puncturing or piercingdevice 3 which serves to puncture the material of the bag 1 above thelevel 6 of the charge 6a so that the interior of the closed bag abovethe level 6 can communicate with the surrounding atmosphere. In theillustrated embodiment, the piercing device 3 is designed to provide thebag 1 with an elongated horizontal slit 4 which is shown in FIG. 2, thisslit serving as an outlet for evacuation of air above the level of thecharge when the bag reaches a second station II which is an evacuatingand sealing station and is shown in FIG. 1c. The walls 5 of the neckportion of the filled bag 1 converge toward the closed top end 1b andthe closed bottom end 1a rests on a suitable conveyor 100 which servesto transport the bag 1 from the station I toward, past and beyond thestation II. The conveyor 100 can be driven intermittently or constantlyand is free to advance a freshly filled bag 1 as soon as the latter issevered from the tube 2t by the knife 2b. During transfer from thestation I to station II, the filled bag 1 is preferably subjected to ashaking or vibrating action so that the charge 6a settles in a manner asshown in FIG. 1b wherein the level 6' of settled charge 6a is below thelevel 6 of FIG. 1a. The means for shaking the bag 1 may comprise one ormore vibrators 101 each of which is operatively associated with theconveyor 100. Other shaking means may be used if desired. It is furtherclear that the bag 1 can be transferred from station I to station II byhand and that the operator can shake the bag during such transfer.

The station II accommodates evacuating means for expelling air above thelevel 6' and sealing means for sealing the bag 1 directly above thelevel 6 so that the interior of the thus sealed bag 1' (see FIG. iscompletely filled with the settled charge 6a and the bag 1' preferablyresembles a brick-shaped or parallelepiped body which can be readilystacked in boxes, crates or on shelves. The station II furtheraccommodates a severing means in the form of a cutter 29 which serves toremove the topmost part 30 of the bag 1' and to leave only a shortwelded seam 1b which can lie fiat aganst the top panel 10' of the bag1'. During evacuation of air via slit 4. the bag 1 is lifted off theconveyor 100 but is deposited thereon again upon severing of the topmostpart 30 so that the resulting bag 1' thereupon advances to storage or toa packing station (see FIG. 1d).

The slit 4 which is formed by the piercing device 3 of FIG. la can beprovided in addition to or as a substitute for a different outlet 31which is shown in FIG. 2. The outlet 31 is defined by the closed top end1b of the bag 1, i.e., the electrodes 2 at the station I may be designedin such a way that they leave one or more paths (outlets 31) in theclosed top end 1b to permit evacuation of air at the station II. Thepiercing device 3 can be dispensed with if the electrodes 2 are designedto provide the top end 1b with one or more outlets 31. It is equallypossible to design the electrodes 2 in such a way that they form anairtight top end 11) and to use only the piercing device 3 or two ormore piercing devices.

Of course, and if the material of the bag 1 is permeable to air but iscapable of preventing escape of the charge 6a, the piercing device 3 maybe dispensed with and the electrodes 2 may form an airtight closure. Atthe station II, the bag 1 is thereupon simply deformed in such a waythat it forms the top panel 10 and is sealed at 1b to be converted intoa block-shaped body 1 which is completely filled with the material ofthe charge. The utilization of air-permeable bags is particularlydesirable when the charge consists of granules, balls, pellets orfragments which cannot pass through the pores or interstices of the bag.

In accordance with another feature of my invention which will be readilyunderstood by referring to FIGS. la to 1d, the closing electrodes 2 maybe dispensed with, i.e., the bag 1 can be transported from the station Ito station II with its top end open. The piercing device 3 may bedispensed with or, if used, it operates in synchronism with the knife 2band electrodes 2a to provide the top part 5 with one or more outlets forescape of air at the station II.

Referring now to FIG. 3, there is shown an assembly 7 which isaccommodated at the station II of FIG. 10 and serves to expel air fromsuccessive bags 1 prior to formation of the seals 1b. This assembly 7comprises evacuating means including two jaws or grippers 12, 13 andsealing means including two sealing electrodes 25. The jaws 12, 13 arecarried by the downwardly extending free end portion or head 11 of anarm 8 which constitutes a carrier for the jaws and is rockable about ahorizontal shaft 9. The arm 8 is biased by a return spring 10 whichtends to rock it in a clockwise direction and is attached to a fixedframe member 10a. This frame member 10a further carries an adjustablestop 23 which determines the upper end position of the head 11. The jaws12, 13 are mirror symmetrical with reference to a vertical plane whichis normal to the plane of FIG. 3 and are movable up and down with thehead 11 as well as toward or away from each other. The upper endportions of the jaws 12, 13 are respectively fixed to horizontal shafts22, 19 which are journalled in the lower part of the head 11 andrespectively carry mating gears 21, 20. The shaft 19 is furtherconnected with a motion transmitting lever 14 having at its upper end afollower 16 which tracks the convex face 17 of a cam 170. A spring 15 isarranged to permanently bias the follower 16 against the cam face 17.The cam 17a is attached to a reciprocable driver 18. The lever 14 willbe rocked in a counterclockwise direction, as viewed in FIG. 3, when thedriver 18 is moved in a direction to the left whereby the shaft 19rotates the gear 20 in a counterclockwise direction and the gear 20rotates the gear 21 and shaft 22 in a clockwise direction so that thejaws 12, 13 move apart as indicated by arrows. When the spring 15 isthereupon allowed to dissipate energy (i.e., to contract), the jaws 12,13 will return to the positions shown in FIG. 3 and will grip the topend 1b of a bag 1 which has been advanced from station I to the stationII. In the embodiment of FIG. 3, the conveyor of FIGS. la-ld is replacedby a conveyor having a series of buckets 23 (one shown) which can moveup and down at the station II to participate in upward movement of thebag 1 when the latters top end 1b is gripped by the jaws 12, 13 and thearm 8 turns in a clockwise direction to move its head 11 toward the stop23. The means for moving the arm 8 in a clockwise direction may comprisea double-acting pneumatic or hydraulic cylinder 8a having a piston rod8b which bears against the arm 8 and can move the latter against theopposition of the spring 10.

The electrodes 25 are disposed at a level below the jaws 12, 13 and aremovable toward and away from each other by a suitable mechanism 25a. Thecutter 29 is disposed above the electrodes 25 to sever theaforementioned topmost part 30 (see FIG. 1c).

The operation is as follows:

When a bag 1 approaches the station II, the electrodes 25 are held inspaced-apart positions so that the piston rod 8b can move the jaws 12,13 to a lower end position in which the jaws extend into the spacebetween the electrodes 25. In the next step, the driver 18 is caused toperform a leftward stroke to move the jaws 12, 13 apart so that the jawsdefine between themselves a gap which can receive the closed top end 1bof the bag 1. The driver 18 then performs a rightward stroke so that thespring 15 returns the jaws 12, 13 to gripping positions, i.e., the jawsgrip the top end 1b in such a way that the outlet'31 (FIG. 2) remainsfree and that air is also free to escape through the slit 4. The pistonrod 8b is then withdrawn whereby the spring contracts and rocks the arm8 in a clockwise direction to lift the jaws 12, 13 together with thebag 1. The bucket 23 follows such movement of the bag 1 and theelectrodes 25 begin to move toward each other. Thus, the walls 5 of theneck portion are folded over the charge 6a and the electrodes 25cooperate with the jaws 12, 13 to assist in expulsion of air above thelevel 6' of the compacted charge 6a. The operation of the mechanism 25ais synchronized with the operation of cylinder 8a in such a way that thejaws 25 close and apply heat and sealing pressure at the moment when thehead 11 abuts against the stop 23. At the same time, the cutter 29severs the bag 1' above the electrodes 25 so that the jaws 12, 13 merelyhold the severed topmost part 30 (FIG. 1c). The electrodes 25 are thencaused to move away from each other and the bucket 23 descends with thebag 1. This completes a full cycle and the assembly 7 of FIG. 3 is thenready to start a new cycle and to convert a fresh bag 1 into a bag 1'.

FIGS. 4a to 4d illustrate the four important stages in the operation ofjaws 12, 13 and sealing electrodes 25. In FIG. 4a, the head 11 for thejaws 12, 13 extends into the space between the moved-apart electrodes 25and the cutter 29 is retracted. The jaws 12, 13 are open and the closedtop 1b of the bag 1 extends into the gap between the jaws. The stage ofFIG. 4b is an intermediate stage. The jaws 12, 13 grip the top end 1band the electrodes 25 engage and deform the walls 5. The electrodes arepreferably rounded, as shown as 28, to avoid damage to the bag. Thestage of FIG. 40 is similar to that of FIG. 3. The electrodes 25 engagethe horizontal top panel of the bag and are about to form a welded seam.The knife 29 approaches the material of the bag in the region betweenthe jaws 12, 13 and the electrodes. In FIG. 40, the jaws 12, 13 havereached their upper end positions and the top part of the bag 1 containsvery little air. In FIG. 4d, the jaws 12, 13 are moved apart so thatthey have released the topmost part 30 and the formation of the seam 1bdirectly above the level 6 of the charge 6a is completed. The bag 1 isready to descend with the bucket 23 as soon as the mechanism 25a movesthe electrodes 25 apart.

If desired, the seam 1b (formed by the sealing electrodes 25) can bebonded to the top panel 1c of the bag 1', for example, by means of aheated ram or plunger 37 which is shown in FIG. 1d. Of course, theelectrodes 25 will form the seam 1b at a level below the slit 4 6 (FIG.2) or in the region of this slit to make sure that the slit disappearswhen the formation of the bag 1 is completed.

It was found that my present invention can be practiced with particularadvantage by resorting to an apparatus which is provided with a machinecapable of converting a web of heat-scalable synthetic thermoplastic orplasticcoated material into a tube 2! and has a mandrel 2m whichintroduces measured amounts of flowable material into spaces providedabove transverse seams (closed bottom ends 1a" in FIG. 1a) formed bysuitable electrodes, such as the electrodes 2a of FIG. 1a. The tube 21is preferably fed downwardly and the finished bags 1 are transportedfrom the station I to station 11 in a fully automatic way, preferably bya conveyor whose operation is synchronized with the operation ofelectrodes 2a, knife 2b, and the assembly 7 of FIG. 3.

The bags may consist of any suitable heat-sealable material or of amaterial which is coated with a heatsealable substance. Polyethylene isone of the materials which can be used in the practice of my invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic andspecific aspects of my contribution to the art and, therefore, suchadaptations should and are intended to be comprehended within themeaning and range of equivalance of the claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. A method of filling deformable receptacles with flowable material,comprising the steps of introducing into a receptacle whose top andbottom ends are respectively open and closed a charge of flowablematerial so that such material fills the interior of said receptacle toa desired level below the top end thereof; closing said receptacle atthe top end thereof; providing the receptacle with at least one outletopening for air between the closed top end thereof and the level of thecharge; removing air located in said receptacle between said closed topand the level of said charge by compressing a portion of said receptacleimmediately above said level whereby air entrapped in the receptaclebeneath the closed end thereof will escape through said outlet openingduring said removing step; sealing said thus compressed portion of saidreceptacle immediately above said level; and severing the portion of thereceptacle above the sealed portion thereof from the filled remainder ofthe receptacle.

2. A method as defined in claim 1, and including the step of engagingthe material of the receptacle above said level to move such materialagainst a top surface of said charge prior to sealing the receptacleimmediately above said level.

3. A method as defined in claim 2, wherein said material introducingstep is carried out at a first station and further comprising the stepof transporting the filled receptacle to a second station prior to saidsealing step.

4. A method as defined in claim 3, further comprising the step ofshaking the receptacle during transfer between said stations to compactsaid charge.

5. A method as defined in claim 3, wherein said receptacle consists offoraminous material which retains the material of said charge butpermits the passage of air.

6. A method as defined in claim 3, wherein the step of providing thereceptacle with at least one outlet is carried out simultaneously withsaid closing step.

7. A method as defined in claim 3, wherein the :step of providing thereceptacle with at least one outlet comprises piercing the receptacleabove said level.

8. A method as defined in claim 3, wherein the receptacle consists ofheat-sealable material and said sealing step includes the application ofheat and pressure.

9. The apparatus as defined in claim 16, wherein said grippers haveparallel shafts journalled in said carrier and mating gears provided onsaid shafts, and further comprising means for rotating one of saidshafts.

10. In an apparatus for filling bags or analogous deformable receptacleswith flowable material wherein charges of a fiowable material areintroduced through the open top ends of successive receptacles so thatthe thus filled receptacles contain fiowable material below and airabove a desired level, in combination, closing means for closing thetops of successive receptacles; sealing means for sealing thereceptacles directly above said level so that each charge completelyfills the interior of the thussealed receptacles, said sealing meanscomprising a pair of welding electrodes and means for moving saidWelding electrodes toward and away from each other so that theelectrodes deform the material of a receptacle over the top surface ofthe charge during movement toward each other; and means for providing anair outlet opening in the material of the receptacle above said sealingmeans to permit expelling of air from said receptacle during movement ofsaid welding electrodes toward each other.

11. The apparatus as defined in claim 10, further comprising cuttermeans for severing the topmost parts of receptacles directly above saidsealing means.

12. An apparatus as defined in claim 10, wherein said last-mentionedmeans comprise piercing means for puncturing the receptacles above therespective charge.

13. An apparatus as defined in claim 12, wherein said closing means andsaid piercing means are remote from said sealing means, and furthercomprising conveyor means for transporting punctured receptacles fromsaid closing and piercing means to said sealing means.

14. An apparatus as defined in claim 10, and including means forgripping and moving upwardly the top end of a filled receptacle while atop portion of the receptacle is located between said electrodes whichare arranged to engage and to deform the material of the receptacleabove said level to move such material against the top surface of thecharge prior to forming a seal directly above said level.

15. An apparatus as defined in claim 14, wherein said gripping andmoving means comprise a carrier, means for moving a portion of saidcarrier up and down, a pair of grippers mounted on said carrier formovement therewith and arranged to engage the top end of a receptacle,and means for opening and closing said grippers.

16. The apparatus as defined in claim 15, wherein said carrier isrockable about a fixed horizontal axis and said grippers are mounted onsaid carrier at points remote from said axis, the means for moving saidcarrier comprising resilient means for biasing the carrier in a sense tomove said grippers upwardly and said grippers being mirror symmetricalwith reference to each other.

References Cited UNITED STATES PATENTS 2,292,295 8/1942 Royal 53-222,387,812 10/1945 Sonneborn et al. 53-22 2,481,611 9/1949 Moore 53-373 X3,196,587 7/1965 Hayward et a1. 53-22 X FOREIGN PATENTS 1,191,283 4/1965Germany.

TRAVIS S. McGEHEE, Primary Examiner US. Cl. X.R. 53-22, 372, 373

